The present invention relates to a connector for use with corrugated tubing, and more specifically but not exclusively, to a connector including an 0-ring for sealing corrugated tubing to said connector.
Corrugated tubing is widely used as a conduit in the gas industry and it is a common requirement that such tubing is easily and hermetically attachable to a multitude of devices. As a result, many different forms of hermetically sealable connectors for use specifically with corrugated tubing exist, the desirable characteristics of which include ease of manufacture and assembly, and durability and maintainability of the seal during use.
An example of a connector for corrugated tubing is disclosed in EP 0 853 742 B1 which describes a fitting including a locating sleeve. The fitting is installed by cutting the tubing in a valley in the surface of the tubing and placing a nut over the tubing. Two split ring washers are placed in a valley adjacent to the cut end of the tubing to restrict movement of the nut. The body is aligned with the tubing by placing the locating sleeve connected to the body in the tubing. The nut engages threads on the body and as the nut is tightened, a tapered end of the body engages the cut end of the tubing and flares the cut end of the tubing. The fitting makes a flared metal-to-metal seal by folding the convolutions of the tubing back against itself creating a double flare without the need for flaring or flattening tools. In the context of this technical field, the term flaring and derivatives thereof refers to the action of an end of a corrugated tube being urged against a clamping face, said face tapering radially outward and in a direction forward of said tubing such that at least one tubing corrugation collapses axially and said tube end is urged and then subsequently clamped interiorly of said tube.
A further example of prior art in this field is U.S. Pat. No. 4,674,775 which describes a coupling for a corrugated conduit including a main tubular body with a sleeve defining a conduit receiving bore terminating at its inner end in an annular shoulder projecting radially inwardly of the tubular body. A nipple clamps the end portion of the conduit and, upon rotation of a nut, said nipple is pressed forwardly forcing the conduit into the shoulder at which point corrugations left projecting beyond the nipple are collapsed between the forward end of the nipple and the shoulder. At the juncture of the shoulder and the conduit is an annular groove receiving a sealing ring for improving the sealing effect between the shoulder and the conduit end.
A disadvantage of EP 0 853 742 B1 lies in the reliance on the integrity and durability of just a flared metal-to-metal seal. A disadvantage of U.S. Pat. No. 4,674,775 lies in the reliance on the sealing qualities of a non-flared metal-to-metal seal.